Fluid fuel burner



Feb. 18, 1941. T. H. SMOOT 2,232,040

FLUID FUEL BURNER Filed July 10, 1959 2 Sheets-Sheet 1 T. H. SMOOT FLUIDFUEL BURNER Filed July 10, 19259 Feb. 18, 1941. 2,232,040

2 Sheets-Sheet 2 2' 'umreo STAT Patented Feb.

FLUID FUEL BURNER Application July 10,1939, Serial No. 283,662

, A 9 Claims.

The invention relates to a fluid fuel burner.

An object of the invention is to provide a simple, practical andefficient oil burner equipped with an oil spray nozzle and with meansfor enveloping the oil spray in a helically discharged rotating envelopof air having sufllclent turbulence for causing the fine misty oil sprayand air to intimately commingle and thoroughly mix.

A further object of the invention is to provide an oil burner'equippedwith helical air directing passages and adapted to deliver air to thesaid passages under sufllcient pressure and velocity to impart to theair the desired rotating motion for producing the necessary turbulenceof flow for intimately mixing the air and oil spray.

It is also an object of the invention to provide means for varying thecross-sectional area of the helical passages, so that, when the feed ofthe fuel is reduced, the volume of air may be correspondingly reducedwithout reducing the velocity of the air passing through the helicalpassages, whereby the velocity of the air and the direction thereof maybe maintained so that the air when free to pass through the helicalpassages will always be discharged with the force required to producethe desired rotary motion and turbulence for producing an intimatemixture of the oil spray and air.

A further object of the invention is to provide means operableexteriorly of the oil burner for adjusting the air controlling meanssubstantially micrometrically from a full open position toa position inwhich the spiral air passages will be entirely closed.

With these and other objects in view, the invention consists in theconstruction and novel combination and arrangement of parts hereinafterfully described, illustrated in the accompanying drawings and pointedout in the claims .hereto appended, it being understood that variouschanges in the form, proportions and minor details of construction maybe resorted to without departing from the spirit or sacrificing any ofthe advantages of the invention.

In the drawings:

Figure 1 is an end elevation of an oil burner constructed in accordancewith this invention.

Figure 2 is a longitudinal sectional view of the- Figure 4 is a detailtransverse sectional view.

taken substantially on the line 4-4 of Figure 2.

Figure 5 is a similar view-taken on the line 5-5 of Figure 2.

Figure 6 is a detail sectional view taken on the line 6-6 of Figure 2.

Figure 7 is a detail horizontal sectional View illustrating another formof air regulator.

Figure 8 is an enlarged detail sectional view illustrating the means foradjusting the operating rod of the air regulator.

In the accompanying drawings in which is i1- lustrated the preferredembodiment of the invention,the oil burner comprises in its constructiona horizontally disposed cylindrical blast tube I provided at its frontend with a nose 2 and having its rear end closed by a circular cap orcover 3 provided at its periphery with an annular flange 4 which isfitted over the rear end of the blast tube and detachably secured to thesame by any suitable means which will permit the cover and theassociated parts to be readily removed as a unit,- as hereinafterexplained.

The blast tube isconstructed of any suitable material and the nose 2which consists of a cylindrical section is preferably in the form of acasting provided at the front with an opening 5 and having at its innerend an interior annular recess 6 which receives the frontend of the bodyportion of the blast tube, the nose being secured to the tube in anysuitable manner.

The nose is provided with an annular surface"! radially inclined to theaxis of the tube, which extends' from the cylindrical portion of thenose to the opening 5 forming an outwardly tapering outlet. The blasttube is supported by a front centrally arranged leg 8 and a pair oflaterally spaced rear legs 9. The legs, which are suitably secured attheir upper ends to the blast tube at the bottom and' sides thereof, maybe constructed of any suitable metal and the legs are approximatelyU-shaped in cross section. The front leg is substa'ntially straight andvertical, while the rear legs are approximately L-shaped and haveinclined upper portions and vertical lower portions. The upper portionsextend downwardly and outwardly from the sides of the blast tube andspace the lower vertical portions from each other.

Each leg is provided at its lower end with a threaded opening preferablyformed by a nut Ill and receiving a vertical screw 1 I having a head i2at its lower end and passing through a leg clamp l3 and adapted to beadjusted to vary the length of the leg so that the blast tube may bereadily leveled and set in a horizontal position.

The leg clamp I3 which is constructed of suitable metal is secured tothe supporting surface and is provided with an approximately L-shapedarm or portion l4 through which the screw passes and which is engaged atits under side by the head I! of the screw at its upper face by a jamnut i5 for locking the screw in its adjustment.

The leg clamps may be secured to the supporting'surface in any desiredmanner and the adjustment of the front and rear legs will enable the oilburner to be accurately positioned for tal fuel pipe I 6 provided at itsfront end with a nozzle i1 and extending rearwardly from a pointrearwardly spaced from the opening 5 to the rear portion of'the blasttube and provided adjacent the cover 3 with an elbow l8 which connectsthe fuel pipe It with the pump line I! of a centrifugal pump l 9. Thecentrally arranged horizontal fuel pipe is supported within the blasttube by an air regulator comprising a fixed annular support 20, acylindrical member II, and an annular series of blades or vanes 22having heliooidal surfaces. The circular support 20 consists of a diskhaving a central opening 23 to receive the fuel pipe l6 and an annularperipheral flange 24 arranged in spaced relation with the inner surfaceof the blast tube. The cylindrical member 21 is suitably secured at itsrear end to the peripheral flange 24 of the circular support 20 andextends forwardly therefrom.

The blades 22 of the annular series extend radially from the cylindricalmember 2| to the inner surface of the blast tube and are suitablysecured at their inner longitudinal edges to the said member 2|. Theseblades form helical p'assages tor the air and the velocity of the airimpinging against the helicoidal surfaces of the blades 22 impart-s tothe air a rotating motion, which will induce so much turbulence of flowthat the fine misty oil spray and air are intimately mixed.

The size or cross-sectional area of the helical.

air passages is adjusted by means of -an annular series ofstraightlongitudinal blades 25, which are secured to a slidable support 26 ofsubstantially the same construction as the fixed support 20 andconsisting of a disk having a central opening to receive the fuel pipeand provided at its periphery with an annular fiange 21 to which thestraight longitudinal blades 25 are secured. The slidable support 26 isprovided at its center with a hub 28 which is slidably mounted on thefuel pipe.

The slidable support 25 is connected to the front end 29 of an operatingrod 30 by nuts 3| and 32 arranged on the front end of the rod, which isthreaded for the reception of the said nuts, The nuts 3| and 32 clampthe front end of the operating rod to the slidable support and the rod30 passes through an opening 33 in a guide 34 extending from the fuelpipe and provided with a clamp 35 for securing it to the same. The rearend 36 of the operating rod' 30 is threaded and is engaged by aninteriorly threaded adjustable thimble 31, which is mounted on the cover3 and which is adapted to be rotated exteriorly of the cover foradjusting the longitudinal blades 25. The thimble 31 is swiveled to thecover 3 preferably ,by a detachable plate 38, and it is provided in itsouter end with a groove 33 adapted to receive a screw driver or othertool for rotating the thimble, which provides substantially a micrometeradjustment for the air regulator. By adjusting the straight longitudinalblades forwardly and rearwardly, the cross-sectional area of the helicalpassages is varied without varying the configuration of the blades orvanes against which the air impinges, so that the adjustment of the airdistributor will cause different volumes of air to pass through the airdistributor at a uniform velocity and without any change in thedirection of the air. By this means the air maybe controlled to suit theadjustment of the fuel control, so that, when an adjustment is made toreduce the amount of fuel discharged by the nozzle, the volume of airsimultaneously discharged may be reduced without lessening the velocityof the air or causing any change in the direction of the discharged air,whereby the discharged air, whether the amount is the full capacity ofthe air regulator or a less amount, will be discharged with the samerotary motion and will envelop the oil spray and produce suflicientturbulence to cause an intimate inixture of the air and oil spray.

Mounted on the fuel tube at the rear portion thereof is a cable support40, which is preferably in the form of a clamp and which receives cables41 extending from a transformer 42 to rightand left-hand electrodes 43located at opposite sides of the, front portion of the fuel tube. Theelectrodes are supported by an electrode holder 44 mounted on the fueltube and extending from opposite sides thereof and having side clamps 45for holding the electrodes. Any suitable form of electrode holder may beemployed, and the electrodes are provided with inclined terminals 46extending upwardly and forwardly and spaced apart above the front end ofthe nozzle and adapted to produce sparks for igniting the fuel in theusual manner.

Cables 4| extend through the upper portion of the cover 3 at oppositesides thereof and are provided with insulating bushings 41 having headsat their inner ends and provided at their outer ends with clamping nuts48 for drawing the heads of the bushings tightly into clampingengagement with the inner face of the cover 3, whereby the bushings andthe cables are firmly supported on thecover 3. When the cover 3 isunfastened from the rear end of the blast tube, the fuel pipe, the airregulator, the electrodes and the associated parts may be removed as aunit and the said parts constitute a combustion unit which may bereadily placed within the blast tube and removed therefrom. The blasttube i is provided at its rear portion with a top opening d9, into whichextends the outlet 50 of a volute fan casing 5| mounted upon the rearportion of the blast tube and suitably secured to the same.

The pump I3 is located at one side of the fan casing and is connectedtherewith by means of a pump supporting bracket 52. Secured to theopposite side of the fan casing is an electric motor 53 having a motorshaft 54 extending into the fan casing and connected'by a suitablecoupling 55 with the shaft 56 of the pump l9. The coupling 55, which ispreferably in the form of a cylindrical member or shaft section, hasmounted on it a fan 51 which operates in the volute fan casing.

The pump bracket which is preferably in the form of a housing is open atthe bottom and closed at the top and sides and is arranged over an inletopening 58 formed in the upper portion of the side wall of the fancasing at the pump side of the same. The motor and the transformer arebolted or otherwise secured to the fan casing and the transformer isconnected by a section 59 of Greenfield cable or other suitable meanswith the feed wires, not shown, for supplying the motor with electriccurrent.

The fan casing 5| is provided at its lower portion with a curved cut-offplate 60 extending upwardly from the front end of the opening 49 in thetop of the blast tube I and secured at its upper end to the upperportion of the fan casing adjacent the bottom of the inlet opening 58.The cut-ofl' plate 60 gradually converges downwardly towards the fan andconstricts the air passage leading to the outlet 50 of the fan, which isadaptedto supply to the blast tube air havin the desired velocity andvolume, and it is capable of maintaining a steady, uniform air pressurewithin the blast tube. 1 1

Referring now to Figure '7, adjustable air regulating blades 6| areprovided at their front ends with angularly disposed terminal portions62, which are arranged in substantial parallelism with helical surfacesof the blades 63 in each adjustment ofthe longitudinal air regulating orcontrolling blades 6|.

Various other forms of blade or air regulating or controlling elementmay be employed for varying the cross-sectional area of the air passagesfor maintaining the velocity of the air without changing its directionwhen the volume of air is varied to correspond to changes 'oradjustments of the fuel feed. I

The blast tube is provided at the bottom with a drain opening 61, whichmay be formed in the nose 2 at the bottom thereof, as clearlyillustrated in Figure 2 of the drawings, but it may be provided at anyother desired point.

The burner of the present invention is not only adapted for burning oilas a fuel, but gas or any other analogous or equivalent fluid fuel maybeused. I

What is claimed is:

1. In a fluid fuel burner, in combination, a blast tube, a fuel pipelocated within the blasttube and provided with a nozzle, and an airregulator including a series of blades having helicoidal surfacesdefining a series of helical air passages surrounding the fuel pipe inrear of the nozzle for imparting rotary motion to air passing throughthe blast tube, and means for varying the effective cross-sectional areaof the helical passages to maintain the velocity and the direction ofthe air passing through the passages constant while varying the Volumeof the air passing through the blast tube. I s

2. In a fluid fuel burner, in combination, a blast tube provided at thefront end with an opening and having an annular surface radiallyinclined to the axis of the tube at the said opening forming a forwardlyand inwardly tapered outlet, a fuel pipe located within the blast tubeand provided with a nozzle spaced from the outlet of the blast tube, andan air regulator including a series of blades having helicoidal surfacesdefining an annular series of helical air passages surrounding the fuelpipe in rear of the nozzle for imparting rotary motion to air passingthrough the blast tube, and means for varying the effectivecrosssectional area of the passages to maintain the velocity and thedirection of the air passing through the passages constant while varyingthe volume of air passing through the blast tube.

3. In a fluid fuel burner, in combination, a blast tube, a fuel pipelocated within the blast tube and provided with a nozzle, and. an airregulator including an annular series of blades having helicoidalsurfaces and arranged around the fuel pipe in spaced relation in rear ofthe nozzle and forming helical air passages adapted to impart a rotarymotion to air passing through the blast tube, and means for varying theeffective cross-sectional area of the helical air passages to maintainthe velocity of air passing through the helical passages constant whilevarying the volume thereof.

4. In a. fluid fuel burner, in combination, a blast tube, a fuel pipelocated within the blast tube and provided with a; nozzle, and an airregulator including a series of blades, having helicoidal surfaces andarranged around the fuel pipe in spaced relation in rear of the nozzleand forming helical air passages adapted to give a. rotary motion to'air passing through the blast tube, and blades tube, a fuel pipelocated within the blast tube and provided with a nozzle, and an airregulator including an annular series of blades having helicoidalsurfaces and arranged around the fuel pipe in spaced relation in rear ofthe nozzle and forming helical air passages adapted to give a rotarymotion to air passing through the blast tube, and longitudinallyslidable blades movable across the air passages for varying theeffective cross-sectional area of the same.

6. In a fluid fuel burner, in combination, a blast tube, a fuel pipelocated within the blast tube and provided with a nozzle, and an airregulator including a series of blades having helicoidal-sur.- faces andarranged around the fuel pipe in spaced relation in rear of the nozzleand forming helical air passages adapted to give a rotary motion to airpassing through the blast tube, longitudinally slidable blades movableacross the air passages for varying the effective cross-sectional areaof the same, an operating rod having a threaded rear end, means forconnecting the front end-of the rod with the slidable blades, and arotary thimble having a threaded engagement with the rear end of the rodfor adjusting the slidable blades.

7. In a fluid fuel burner, in combination, a blast tube, a fuel pipelocated within the blast tube and provided with a nozzle, and an airregulator including a. fixed circular support surrounding the fuel pipe,an annular series of blades having helicoidal surfaces carried by saidsupport and forming helical air passages adapted to impart rotarymovement to air passing through the blast tube, and adjustable bladesmovable across said air passages for varying the effectivecross-sectional area of the same. 1

8. In a fiuid fuel burner, in combination, a blast tube, a fuelpipelocated within the blast tube and provided with a nozzle, and an airregulator including a fixed support, a series of blades havinghelicoidal surfaces mounted on the fixed support and forming helical airpassages around the fuel pipe, a slidable support surrounding the fuelpipe, and longitudinally slidable blades mounted on the slidable supportand arranged to move across said helical air passages to vary theeffective crosssectional area of the same.

9. In a fluid fuel burner, a blast tube, a fuel pipe located within theblast tube and provided with a nozzle, and an air regulator including aseries of fixed blades having surfaces defining a series of air passagesextending generally in the direction of a helix having a central axiscoincident with the axis of the tube, said passages imparting a swirlingmotion to air passing through the blast tube, means for varying theeffective

